In my personal opinion, the most important thing is your motivation. You have to be consistent with your daily routine for achieving your goal. I suggest you first to do listening whatever it is in your language target even though you do not understand it.The purpose is for making your ears common with the words. If you've a target for proficiency, it's much better you take a course. If not, using book and audio such as pimsleur is good for a springboard. Good luck